The present invention relates to a mobile utility scaffold having a locking and securing device for attaching a scaffolding platform side rail to a supporting structure.
Scaffolds are used in many situations to provide an elevated platform for workers. Most scaffolding is made of tubular metal which is welded together to have vertical legs with horizontal rungs extending between the legs to form a ladder-like vertically extending supporting structure. Horizontally positioned platforms are held on side rails which are mounted to the vertically extending support structures.
Since scaffolding is often moved between work stations or is added to as work is completed, it is desired to design and construct scaffolding that is easy to assemble and disassemble and which also is very secure. It is also desired to have scaffolding which is economical to manufacture and is easily collapsed, stored and moved from one work location to another. In the industry, in order to make the scaffolding easy to assemble and adjust, the vertical and horizontal structures are made with tolerances such that the horizontal and vertical structures can be easily placed adjacent another. Since the vertical and horizontal supporting structures are manufactured with dimensions that allow one structure to be moved relative to the other structure, sometimes the resulting scaffold structure can be unreliable, shaky or difficult to secure. One problem is that these assembled scaffolding structures need to have secure locking mechanisms so that the horizontal structures and the vertical structures do not move relative to each other during use.
One type of latch mechanism M currently used by the owners of the instant invention is shown in FIG. 6. An L-shaped pin P is held by a bracket welded to a horizontal support H. The L-shaped pin P extends through a spring S and the pin extends through an opening O in a vertical support V. The L-shaped pin P has a roll pin R adjacent the end of the pin P. To operate, a force is placed on the depending arm of the L-shaped pin P to either push or pull the pin P into or out of the opening O in the vertical support V.
Another type of prior art latch mechanism is shown in FIG. 7. A G-shaped pin G is held by a bracket Bxe2x80x2 welded to a horizontal support Hxe2x80x2. The G-shaped pin G extends through a spring Sxe2x80x2 and extends through an opening Oxe2x80x2 in a vertical support V. The G-shaped pin G has a roll pin Rxe2x80x2 which extends in a vertical direction through one end of the pin G. To operate, a force is placed on the depending curved arm of the G-shaped pin G to either push or pull the pin G into or out of the opening Oxe2x80x2 in the vertical support Vxe2x80x2.
Many other types of latch mechanisms have been used to secure the horizontal platform to the vertical supporting structure. Examples of several of these efforts are shown in U.S. Pat. Nos. 409,167; 4,793,438; 5,028,164; 5,390,761; 5,931,260; 6,202,788 B1 and 6,273,831 B1.
One problem with the current latch mechanisms for scaffolding is that the latch mechanism could become loose or disengaged during use. Often a worker, while standing on the platform, moves about the platform which causes shifting and constant realignment of the horizontal work surface with respect to the vertical supporting structures. This lateral movement of the horizontal work surface could tend to cause the latch mechanisms to become loose or displaced relative to their initial position.
Latch mechanisms that use springs to hold the latch mechanism in position often present further problems. The use of springs has made the latch mechanism more difficult to operate. Typically, a great amount of force is needed in order to overcome the bias of the spring in order to disengage the latch mechanism. Often, the horizontal and/or vertical structure must be secured or stabilized with one hand while the other hand of the worker disengages the latch mechanism. In such situations, the scaffolding must be adjusted at least four individual spots and often times the one side of the horizontal structures are positioned at an acute angle with respect to the vertical structure during this adjustment period, causing undesirable stresses on the still-locked opposing latch mechanism.
Still other problems with the currently used latches occur since the scaffoldings are often used in construction and other work environments where material such as work equipment, debris or supplies are constantly being moved onto and off of the scaffolding. It is important to have a latch mechanism which cannot be accidentally disengaged and further which does not interfere with the movement of the worker, worker""s tools or supplies, or any debris or materials being moved by the worker.
It is therefore an object of the present invention to provide a locking and securing mechanism that is easily secured and, further, is held in a secured locking position.
It is a further object of the present invention to provide a locking and securing mechanism which positively indicates that the mechanism is in a properly secured and locked position.
It is a further object of the present invention to provide a locking and securing mechanism which is inexpensive to manufacture.
It is yet another object of the present invention to provide a locking and securing mechanism which is strong and resistant to breakage or shearing.
It is yet another object of the present invention to provide a locking and securing mechanism which is easy to use and operate with one hand, such that two opposing locking and securing mechanisms can be simultaneously operated by one worker.
It is another object of the present invention to provide a scaffolding which is easy to be assembled and disassembled while also providing a strong and secure work surface for a worker.
It is another object of the present invention to provide a scaffolding in which a horizontal work platform can be quickly moved to new positions relative to vertical support structures.
Still another object of the present invention is to provide a locking and securing mechanism for a scaffolding which securely connects a horizontal work platform to vertical supporting structures of the scaffolding.
It is still a further object of the present invention to provide a locking and securing mechanism that can be used with currently available horizontal support structures and vertical support structures of a scaffolding system.
Yet another object of the present invention is to provide a scaffold assembly in which the platform securely held in horizontal position without moving out of place or becoming disengaged during use of the platform.
Additional objects, features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment as described herein.
A device for locking and securing a first support to a second support is described. The locking and securing device includes a means for securing the first support to the second support. The securing means is moveably attached to the first support such that the securing means is moveable between a secured position and an unsecured position with respect to the second support. A force is applied at a substantially a center point of the securing means in order to move the securing means. The securing means has a handle positioned at a substantially center point of a securing pin for receiving the applied force.
The locking and securing device further includes a means for locking the first support to the second support. In one embodiment, the locking means is integrally formed with the securing means. During operation of the locking and securing device, the securing means is rotatably moveable about a longitudinally axis extending through the securing means. The securing means is also longitudinally moveable along the longitudinal axis such that the securing means is moved between the secured and unsecured positions and the locking means is moved between the locked position and the unlocked position.
In one aspect, the locking and securing device comprises an engagement member and a securing mechanism. The securing mechanism includes a longitudinally extending securing pin and a handle positioned in a substantially centered relationship with respect to the securing pin. The securing mechanism further includes a locking member positioned on the handle in a spaced apart relationship to the securing pin.
The securing pin extends through an opening in the engagement member such that the locking member is engageable with the engagement member when the locking member is in a locked position.
In one embodiment, the securing pin defines a radially extending opening at a midpoint of the securing pin for receiving a rivet pin. A first biasing means is axially positioned on the securing pin between the rivet pin and a first end of the securing pin. A second biasing means is axially positioned on the securing pin between the rivet pin and a second end of the securing pin.
In another embodiment, the scaffolding system comprises at least one horizontal support and at least one vertical support and a locking and securing device lock for securing and locking the horizontal support to the vertical support.